First of all, it's Vienna, not Venice. And you don't need a counterfactual Vienna to compare it to cities of similar size and economic characteristics.
> the best they could do would be to get rid of the (actually quite small) cut that landlords take for themselves
Again, I think this claim is easily contradicted by the success of Vienna's housing market. The thing is, if you took the market as it is today, and the government just bought all the housing properties at market rates, then yes you would only see savings in terms of the profit margin which is currently enjoyed by landlords. But if the government takes the role of providing housing as a public good, it can change the incentive structure of the market in a way which benefits renters.
For instance, if your goal is to maximize rent profits, you will make decisions to maximize the year-over-year increase in rent, and you will build more units in a way which maximizes the rental price per unit. That's how you end up with so many shoebox-sized luxury condos in Toronto that nobody really wants and an under-served affordable housing market. If you treat housing as a public good, you make decisions to keep rent prices stable, and you build more housing to serve the need rather than the profit motive.
>If you treat housing as a public good, you make decisions to keep rent prices stable, and you build more housing to serve the need rather than the profit motive.
This argument strikes me as the tail wagging the dog. Vienna has no motive to limit housing since they build such an enormous percentage of it. If rents go up because the government of Vienna doesn't build enough housing, they will be removed from office. Profit is profit. Developers will build anything and everything that they can. The issue lies in the extreme costs involved in building anything new at all, mostly in graft by local municipalities and residents. If a municipality with a broken real estate market allowed housing to be built with less effort, more housing would be built.
Forty percent of Manhattan's buildings could not be built today.
So would you advocate that there be no zoning/building regulations? The article you linked has a slightly misleading title; it would be more accurate to say: "with today's zoning laws, 40% of the buildings in Manhattan would have been replaced by slightly smaller buildings which allow more light to reach the street." I already find Manhattan overly dense, and I can imagine those regulations were put in place for good reason.
In Berlin, we have had laws on the books forever which prevent tall buildings and excess density, and I'm glad because if developers had their way, they would build high-rises where all the parks currently are, and this would not be a city I would want to live in.
In general I'm not a fan of over-regulation or excess government intervention, but when it comes to housing, I think it does make more sense to treat it as a public good. Government is not perfect, but people should have some voice in how their community develops, and this will not be the case if housing development is left only to private interests.
> the best they could do would be to get rid of the (actually quite small) cut that landlords take for themselves
Again, I think this claim is easily contradicted by the success of Vienna's housing market. The thing is, if you took the market as it is today, and the government just bought all the housing properties at market rates, then yes you would only see savings in terms of the profit margin which is currently enjoyed by landlords. But if the government takes the role of providing housing as a public good, it can change the incentive structure of the market in a way which benefits renters.
For instance, if your goal is to maximize rent profits, you will make decisions to maximize the year-over-year increase in rent, and you will build more units in a way which maximizes the rental price per unit. That's how you end up with so many shoebox-sized luxury condos in Toronto that nobody really wants and an under-served affordable housing market. If you treat housing as a public good, you make decisions to keep rent prices stable, and you build more housing to serve the need rather than the profit motive.